


For Science

by caras_galadhon (Galadriel)



Category: The Avengers (Marvel Movies)
Genre: Established Relationship, Fisting, Humor, Kink, M/M, Orgasm Delay/Denial, Plot What Plot, Voyeurism
Language: English
Status: Completed
Published: 2012-06-06
Updated: 2012-06-06
Packaged: 2017-11-07 01:08:06
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,201
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/425254
Author URL: https://archiveofourown.org/users/Galadriel/pseuds/caras_galadhon
Summary: <blockquote class="userstuff">
              <p>There are few things Bruce enjoys so much as watching Tony come undone under his hands.</p>
            </blockquote>





	For Science

**Author's Note:**

> Written for the [](http://avengerskink.livejournal.com/profile)[**avengerskink**](http://avengerskink.livejournal.com/) [prompt](http://avengerkink.livejournal.com/6021.html?thread=8828805#t8828805), "Bruce fists Tony into submission, until he's crying and moaning on their bed. And Tony loves every second of it...+9000 points if someone overhears, gets worried, and walks in on them...Maybe Thor, that would be cute. :3" Much love and gratitude to [](http://brodeurbunny30.livejournal.com/profile)[**brodeurbunny30**](http://brodeurbunny30.livejournal.com/), [](http://nieninque121.livejournal.com/profile)[**nieninque121**](http://nieninque121.livejournal.com/), [](http://empy.livejournal.com/profile)[**empy**](http://empy.livejournal.com/), [](http://deangirl1.livejournal.com/profile)[**deangirl1**](http://deangirl1.livejournal.com/) and [](http://savageseraph.livejournal.com/profile)[**savageseraph**](http://savageseraph.livejournal.com/) for equal parts consultation, egging me on, and gentle teasing. ♥

"You're sure?" Bruce hesitates, thumb tucked up against his palm, ignoring the urge to push forward, to watch all five of his slick fingers slide home.

"Of course I am." Bruce doesn't have to look up to know Tony's rolling his eyes; he can practically hear them revolve, even above the strained impatience in his voice. "Is there a problem? Because if there's a problem, if you want to back out, I can get JARVIS to do it. I installed some interesting subroutines last time you were away, and I've been tinkering with this new arm that he has complete control of, with these _great_ prosthetics you just slide right over, and while I'm _loving_ the tentacle--"

"Tony."

"--I think I've almost got the articulation perfectly adjusted, so it bends _just so_ , although I'm still working on making the suckers, well, _suck_ \--I'm dying to try out the hand."

" _Tony_."

"There were some initial problems with the underlying structure, but I think I've finally managed to get the fine tuning down pat, and now each and every finger curls right up into a fi-- _Oh god_."

Bruce revels in the tiny thrill that runs through him as he thrusts his fingers shallowly into Tony, shutting him up the only way he knows how. How someone can be so utterly debauched -- naked and sweating, squirming like there's lightning under his skin -- and still natter on like he's the head auctioneer at a cattle sale baffles Bruce, but it's just one in an ever lengthening list of things that fascinate him about Tony and keep him coming back.

"Yeah, like that. Do that again." Bruce bites his lip, muffling a groan as Tony tightens around him. "No. No, scratch that, deeper. I want it _all_. Come on. I'm not going to break."

Bruce clears his throat, keeping his fingers moving just enough to keep Tony's mouth from running off like a freight train, just enough to keep him focussed on Bruce's words. "Tony. Just humour me, here. I need you to listen to me carefully. This is what you want, yes?" If he was called on it, Bruce could say this is all simply about needing to be sure, needing to be cautious and mindful of his partner, making sure they're both on the same page, but he knows -- hell, even the Other Guy knows -- that there's something utterly intoxicating about having Tony half out of his mind with want, reduced to begging and pleading. After all, how many genius billionaire playboy philanthropists have to beg for anything? "Tony?"

Tony swallows a sound that might be very close to a whimper as he blinks the sweat out of his eyes, hair damp and mussed, lips bruised and red from biting. He shudders as he takes a deep breath, then nods. "Yes." Bruce smiles as he watches Tony's chest rise and fall, the faint glow of blue in the dimmed room enough to highlight each curve and plane of muscle. "Yes, please." This time, the sound that escapes is definitely a whimper, and before he can manage another long, slow, calming breath, a jumble of words catches up to him and tumbles out in a rush of need. "I want-- I want-- I need this, Bruce. God, I need it. I--" Tony's tongue flickers over his bottom lip, the gesture as titillating as it is unconscious. "I... Would it help if I said this was for science?"

Unbidden, a chuckle bubbles up from Bruce's chest. "Sure. For science." He nods, tucking his thumb in as tight as he can, letting his hand press gently forward as Tony's body adjusts to the pressure. There's something utterly beautiful about watching Tony open up, watching his hand slowly slip inside, something utterly erotic about the way Tony clenches and groans as he closes around Bruce's wrist. Even better is the way Tony arches his back, hips rising as he thrusts against nothing, hands curling in the bedclothes, twisting every which way. Bruce loves this part, the balance between control and chaos, the vibrating boundary between the two, ever shifting, always a hair away from breaking in a way he never experiences. For Bruce, life is either complete control or complete chaos, the borders drawn, guarded and locked down tight. But in Tony, the two mingle freely, the source of every creative, crazy, courageous impulse the man has.

It's silent now, nothing but Tony's ragged breaths and the hum of the tower around them, the calm before the storm. As tempted as he is to take advantage, to settle into a slow rhythm of short thrusts, it won't be long before Tony objects, frustration overrunning pleasure and turning their evening sour. Instead, he lets his hand curve into a fist, the hitch in Tony's breath not escaping his notice. Ever so carefully, Bruce rocks his fist back and forth, and is rewarded with a deep groan. "Good?"

Tony shivers and nods, tightening around Bruce as he exhales in a shuddering breath. "God, yes. _More_."

Bruce is more than happy to oblige.

He's always a little awestruck at the way Tony comes undone. Each twist of his hand coaxes out a better, more urgent noise, each slight press forward causes a wave of shudders to run down his body. Even as he eases the way, Tony relaxing beneath him, taking each thrust as Bruce firms them up, makes them more powerful, more rapid, more insistent, the silence is broken, moans replaced by cries, and cries with shouts. Before long, Bruce has to lean forward, press his weight down on Tony's hips just to keep him from bucking, keep him still enough so Bruce can keep his fist thrusting forward, and forward, and forward again.

Tony's hands are in his hair, cupping his neck, sliding down his face, dropping to the mattress and stretching above his head. Bruce doesn't look, but he knows Tony's toes are curling, can feel his legs tensing and jerking, and he laughs as his cheek brushes against Tony's cock, the barest of contact making Tony scream.

Whatever he's shouting, whatever words or phrases, whatever curses or prayers to whatever gods or demons Bruce doesn't know. All he knows is that one of Tony's sharpest weapons is his tongue, and right now, in this very moment, he's no longer master of it. _Bruce_ is, and it's as heady a power as he's ever had.

He smirks as he watches Tony's cock twitch, knows from the slickness painting the tip that it's only a matter of time, and wonders briefly if it'd be more fun to have Tony come in his mouth or from his fist alone. He wets his lips, decision almost made, and as he presses deeper into Tony, twisting enough to make Tony utter the most delightful scream--

\--The room floods with light, door wrenched off its frame to the shriek of tearing metal and a battle-cry the likes of which Bruce hasn't heard since... since...

 _Oh god_.

Thor crashes into the room, half-dressed, chest bare, hammer already swinging, expression caught somewhere between concern and rage as he booms, "Whosoever wounds the Man of Iron shall face the wrath of Thor, Mighty God of Thunder!" Tiny sparks dance across Mjolnir's head, crackling ominously as Thor prepares to fight and, just as suddenly, start to fade away. His brow furrows as he takes in the room: the rumpled sheets on the floor; Tony, stretched out and naked as a jaybird, nearly insensible, even to the giant mass of muscle threatening murder in his bedroom; and Bruce, fully clothed, kneeling between Tony's legs, sleeves carefully rolled up, right hand buried in Tony's ass. Thor's eyes widen, his head swivelling like a tripod, and for a long moment, Bruce hopes that he will simply give up the field and back out into the hallway. "...Banner?"

Bruce would bury his head in his hands if he had both free.

"What is the meaning of this?" Thor takes a step towards the bed, then stops stock-still as Tony moans and rolls his head to the side. "Is he ill? Wounded? Might we send for some of your physician colleagues? Perhaps they can apply leeches."

" _More_." Tony shudders, and Bruce can feel him clench around his fist, not anywhere near ready to let him go. Tony opens eyes made heavy with lust, and smirks in Thor's direction as they focus. "Hey, Delta Force. Knock next time, mmkay?" He arches upward, rocking back against Bruce, gasping as he gains the tiniest of inches.

Bruce swallows, caught between Tony's desires and Thor's confusion. "I..." He starts, stops, and tries again. "It's not-- We're-- It's fine. He's fine."

A prickling sensation at the nape of his neck alerts him to Thor's gaze as it slides down Tony's body, curiosity winning out over confusion. As if caught in a slow-motion train wreck, Bruce watches, horrified, as Thor sets down his hammer and crouches by the bed, tipping his head to the side as he examines Bruce's arm. For a long moment, the only sounds are Tony's soft whimpers as he insists on fucking himself, come hell or high water. "...I believe," Thor says, thoughtfully, "that I saw such a technique when my brother gave birth to Sleipnir. I did not know Stark was with child. Perhaps with some assistance--"

"--No. No, it's all right. It's... it's not like that." Bruce swallows and begins to uncurl his fist, silently promising he'll make it up to Tony later. "Tony is fine. We're... enjoying ourselves, and it's all right if you go back to bed. We'll be quieter." As he starts to ease his hand out, Tony groans deeply and tosses his head, gripping Bruce tightly even as he raises his hips, his demand evident in every tiny gesture. Immediately, Thor begins to look alarmed, so Bruce picks the only option he can think of that won't lead to more noises from Tony and more uncomfortable inquiries from Thor: he stops moving entirely.

That works for about a heartbeat, long enough for Thor to relax and Tony to get testy. " _Come on_ ," he moans, "... _fist_..."

Thor's eyebrows go up. "Oh! I understand now!" Bruce can do nothing but breathe a sigh of relief. "My half-brother Tyr once showed his bravery by placing his fist in the wolf Fenrir's mouth." Immediately, the tension returns, and Bruce wonders idly if his shoulders have migrated up to his ears. " _This_ is just such a trial." Thor blinks, squinting a little as he examines Tony and Bruce once again. "I do hope that Stark does not possess teeth in there. Tyr, most unfortunately, lost his hand in the binding." He thumps Bruce on the back, the contact enough of a jolt to have Bruce involuntarily pressing his hand deeper. Tony groans in appreciation.

"No, look. This is..." Bruce isn't even sure why he's trying to explain, but the situation has just become far, _far_ too ridiculous. "Look, it's not important. Just... just go, and don't worry, and... Tony will explain in the morning." He might as well slough it off on Tony; after all, he's the one who tripped the Asgardian alarm in the first place.

Thor stands, and Bruce counts that as a minor win. "But I still do not understand," he mutters, the thunderclouds gathering on his brow hinting that the battle to get him to leave may not yet be over. That's it. Bruce is going to waste away here, his arm halfway up Tony's ass, pummelled to death by awkward questions and disconcerting anecdotes about Thor's family. He can only hope that someone comes to save him before he shrivels away. Maybe Steve... No, the Captain is too genteel to navigate through a situation like this, no matter his diplomacy and tact. Natasha might be able to help him out, if she and Clint weren't off on a reconnaissance mission, and Fury would be more likely to nuke the Stark Tower from orbit than bother to untangle this mess.

Yet just as Bruce is beginning to lose all hope of even a last minute airlift assist from Coulson and the Helicarrier, Tony huffs, focusses fuzzily on Thor and says, "It's for science."

"Oh! Oh, of course." Thor nods, picking up Mjolnir as he makes his way to the door. "I would not wish to interrupt your 'science'." Bruce can almost hear the air quotes, but even so, it gets Thor out of the door, down the hallway, and presumably back to his own room. Thank all the Lords of Asgard, and certainly _not_ the smug bastard grinning at him right now from under a fringe of dishevelled hair.

"So?" Tony smirks and rocks his hips, shivering lightly. "Fabio's gone, and I don't think we're done yet."

Bruce shakes his head. "Of course not." It would figure that Tony isn't going to let a little thing like a curious God get in the way of getting laid. He can feel the edges of his mouth tugging upward in an involuntary smile. "After all, it's for science."

"For science," Tony groans, biting his lip as Bruce curls his fingers back into a fist. "And everyone knows science is sexy."


End file.
